Power driven putty gun



June 7, 1966 N. K. MADSEN POWER DRIVEN PUTTY GUN 2 Sheets-Sheet 1 Filed May 27, 1964 INVENTOR.

NIELS KIRSTE IN MADSEN M MM MM June 7, 1966 MADSEN 3,254,806

POWER DRIVEN PUTTY GUN Filed May 27, 1964 2 Sheets-Sheet 2 [Z l4 l0 WJIIIJIUQJIEIIIIP s w I g INVENTOR- NIELS KIRSTEIN MADSEN United States Patent 3,254,806 POWER DRIVEN PUTTY GUN Niels Kirstein Madsen, 29 Vestergade, Olgod, Denmark Filed May 27, 1964, Ser. No. 370,646 Claims priority, application Denmark, May 30, 1963,

2,570/ 63 6 Claims. (Cl. 222-334) I The present invention relates to a power driven dispenser device for mediums such as plastic substances, for example a putty gun, comprising a dispenser container and a pressing element operable to drive out the medium from said container.

Known hand guns of this type comprise a cylinder having a glide piston and provided with means for introducing compressed air into the chamber behind the piston. The cylinder has a removable end cover provided with a hole in which different forms of nozzles may be inserted. For charging the cylinder the end cover is removed and a putty cartridge is inserted in the cylinder, whereby the piston is pressed back, or the cylinder mouth is connected to a special charging device from which putty is pressed into the cylinder by means of compressed air; also by this method the piston will be pressed back in a passive manner. By less viscid substances such as grease it is also known in the art to fill the cylinder and press the piston back by pressing the grease into the cylinder through a narrow inlet valve.

Both these charging methods are expensive and inconvenient in practice, since the preformed putty cartridges are expensive to use while the special charging device is bound to assuming a stationary position on a building site so as to cause much inconvenient trafiic to and from the charging device.

The object of the invention is to provide a dispenser device which may be charged in an easier, more economical, and more practical manner.

A further object is to provide a dispenser device in the form of a hand gun having power operated means for returning the pressing piston against its initial position.

Still a further object of the invention is to provide a dispenser device in which the pressing piston may be power influenced to carry out its return stroke by means 1 of the same external power source as used for controlling the forward pressing movement of the piston.

Another object of the invention is to provide a dispenser device including an auxiliary pressing chamber so as to obtain a high pressing force on the pressing piston.

Still another object is to provide a dispenser device which is easy to operate and to charge, simple in construction and reliable in operation. These and other objects and advantages of the present invention will appear from the following description, reference being made to the accompanying drawings, in which:

FIG. 1 is a perspective, exploded view, partly in section, of an embodiment of a putty gun according to the invention,

FIG. 2 is a sectional view of the middle portion thereof,

FIG. 3 is a detail seen from below,

FIG. 4 is a side elevation of the gun,

FIG. 5 is a perspective view illustrating the manner of charging the gun,

FIG. 6 is a schematic sectional view through another embodiment of a dispenser device according to the invention, and

FIG. 7 is a corresponding view of a further embodiment.

The embodiment of the gun shown in FIGS. 1-5 comprises two separated cylinder portions provided with interconnected pistons. The gun has a trigger operable to introduce compressed air either into the chamber in front of the rear piston to thereby force the piston system backwardly in a charging movement or into the chambers behind the pistons to thereby force the piston system forwardly in a pressing or working movement.

In more detail, the gun comprises a lengthy cylinder consisting of an open front cylinder 10, a closed rear cylinder 12, and an intermediate socket piece 14 having screw threaded ends in which the cylinders are tightly secured with their ends pressed against sealing rings 15 in the socket piece 14. A piston 16, respectively 18, is located in eachof the cylinders, and these pistons are interconnected by means of a piston rod 20 passing through a central bore 22 in the socket piece 14. Sealing rings 24 are provided at each end of the bore 22 so as to tighten the passage of the reciprocable piston rod through the socket piece 14. The piston rod 20 has a central passage 26 which is open to the rear side of the piston 18 and to the interior of the front cylinder 10 through a side hole 28 just behind the front piston 16, the end of the passage 26 here being closed by means of a screw 29 serving to secure the piston 16 to the piston rod 20.

T hevcylinder portion in front of the front piston 16 is designated with 30, the portion between the socket piece 14 and the front piston 16 with 32, the portion between the rear piston 18 and the socket piece 14 with 34, and the portion behind the rear piston 18 with 36. It will be understood that a flow connection is established between the chambers 32 and 36 by means of the passage 26 and the side hole 28 in the front end of the piston rod 20.

A conical end cover 38 having a screw threaded front hole 40 for receiving a putty nozzle 42 is adapted to close the mouth of the front cylinder 10 and to be released therefrom in the following manner: In the socket piece 14 there is provided a transverse bore 44, the outermost portions of which, designated with 46, are of enlarged diameter. In each of the portions 46 there is mounted a turnable body 48, these bodies being interconnected by means of a pin 50 through the bore 44 and a screw 51. At the end surface of each of the bodies 48 a tab 52 is provided in an excentric position, and two arms 54 extending backwardly from the end cover 38 are swingably secured on these tabs 52 by means of screws 53. One of the bodies 48 is provided with a handle 56 which is swingable between a rear position in which the tabs 52 are located in a rear position just beneath the center line of the pin 50 and a front position in which the tabs 52 assume a correspondingly advanced position, for example just in front of the vertical plane through the pin 50, In the first mentioned, rear position of the tabs 52 a rear skirt portion 39 of the end cover 38 will be drawn into safe engagement with the circumference of the mouth 11 of the cylinder 10, while in the last mentioned front position of the tabs 52 the end cover 38 will be pushed so much forwardly that the skirt portion 39 is released from the cylinder mouth, whereafter the end cover 38 may be swung upwardly and backwardly on the arms 54 around the tabs 52 to the position shown in dotted lines in FIG. 4. In this figure the front position of the end cover is shown in full lines, and it will be noted that the cover rests on the top side of the cylinder mouth 11 by means of a backwardly extending flap 58 adapted to align the end cover with the cylinder in this position so that the end cover may be brought in engagement with the cylinder mouth simplyby turning the handle 56 backwardly from the position shown.

As shown in FIGS. 1, 2, and 3, three vertical bores 60, 62, 64 are provided in the underside of the socket piece 14, and at'the top portions these bores are interconnected by means of a longitudinal channel 66 having tightening means 67 inserted in the free end thereof. The bore 60 is adapted to receive a tube nipple 68 for the Patented June 7, 1966 I introduction of compressed air, while the bores 62 and 64' are provided with identicalvalve mechanisms 70 and 72 to be described in more detail below. A screw threaded lateral bore 74 (FIG. 3) with an enlarged outer portion 76 extends into that portion of the channel 66 which connects the two valve bores 62 and 64. At this place the side bore 74 has a conical bottom portion acting as a valve seat for a needle screw 78 the head of which is provided with ring means 79 for tightening against the interior cylindrical wall of the enlarged bore portion 76 so that the screw 78 may act as adjustable regulationmeans in the flow connection between the'bottom portions of the two valve bores 62 and 64. The middle sectionof the bore 62 is connected to the chamber 32 behind the front piston 16 through a channel 80 (FIG. 3) while the middle section of the bore 64 is correspondingly connected to the chamber 34 behind the socket piece 14' through a channel 82.

Underneath the socket piece 14 there is arranged a pistol grip 90 divided in two halves assembled by means of screws 92 and secured to the socket piece 14 by means of screws (not shown) through suitable holes 94. The pistol grip is provided with groove means 91 for holding the blowing nozzle 68 in such a position that the end thereof projects up into the bore 60, the other end of this nipple being inserted in a flexible tube 96 for connecting the device to a suitable source of compressed air. The nozzle 68 is provided with ring means 69 for tightening against the wall of the bore 60. A trigger member 98 having upper spaced portions 100, 2 for cooperation with the valves 70, respectively 72', is swingably mounted in a pin-and-bracket-suspension 101, I03 so as to be swingable both forwardly and backwardly.

The valves 70 and 72 consists each of a tubular housing 110 having a narrow middle portion 112 provided with radial holes 114, an exterior tightening ring 115 for tightening between the upper portion of the corresponding bore and the said middle portion of the valve, and a tightening ring 116 for tightening between this. middle portion and the free space beneath the valves. The ends of the tubular housing 110 are formed as valve seats 118, 120 adapted to cooperate with valve heads 122,. respectively 124, formed. on a central valve member 126 the length of which is so adapted that one end of the valve is closed when the other end is open and vice versa. The mutual position of the twovalves and the trigger member portions 100, 102 is so adapted that the valve member 126 in both valves is in its lowermost .position, i.e. with the upper valve seat 118 closed when the trigger member assumes its intermediate, neutral position shown in dotted lines in FIG. 2, while the valve member 126 of the valve 70, in the following referred to as the pressing valve, is moved to its opposite position when the trigger is pressed inwardly so that the trigger portion 100 raises the lower valve head 124 into engagement with the valve seat 120; correspondingly the valve member 126 belonging to the valve 72, in the following referred to as the return valve, will be raised to shift the valve position when the trigger 98 is pressed forwardly, this position being shown in full lines in FIG. 2.

When the tube 96 is connected to a suitable source of compressed air the air pressure will be transmitted from the inlet bore 60 through the channel 66 to the upper portions of the valve bores 62 and 64, where the air pressure will serve to close the upper valve portions 118, 122 of the valves 70 and 72 in case the trigger 98 is not influenced byany operating force. Hereby the two valve members will automatically adjust the trigger to assume its neutral position in which the air pressure is not transmitted further than to the said bottom portions of the valve bores 62 and 64.

When the trigger 98 is pressed forwardly by means of a finger behind the trigger, the valve positions will be as shown in FIG. 2, where the valve 70 is closed inthe upper part and open in the lower part thereof, while in the valve 72 the upper part will be open and the lower part closed'. Hereby the air pressure will be transmitted to the interior of the valve 72 and through the radial holes 114 to the exterior of the intermediate valve portions 112. Therefrom the air pressure will be transmitted further through the channel 82 in the socket piece 14 and into the chamber 34 behind the socket piece. It will be understood that the piston system 16, 18, 20 will be forced to move backwardly when compressed air is introduced into the chamber 34 so as to exert a pressure on the front side of the rear piston 18. The corresponding backwardly directed movement of the front piston 16 is used for charging the gun cylinder 10 in a manner to be described below. The chamber 34 may be referred to as the return chamber.

As the piston system moves backwardly the volume of each of the chambers 32, 36 behind the two pistons will be reduced, but no overpressure will be produced since the air from the chamber 32, in the following referred to as the front pressing chamber, may escape through the chanel in the socket piece 14, the intermediate portion of the bore 62, the radial holes 114 in the valve 70, the interior of the valve 70, and the open lower valve portion thereof out into the free space around the trigger member in the pistol grip. The air from the rear or second pressing chamber 36 may escape along the same way after having been pressed out into the front pressure chamber 32 through the piston rod channel 26 and the side hole 28.

As soon as the trigger member 98 is released the upper part of the valve 72 will again be closed due to the weight of the valve member 126- and the air pressure on the upper valve head 122 so that the valve and trigger system will immediately reassume its neutral position.

When the trigger member 98 is pressed inwardly against the pistol grip the position of the two valve members 126 will be opposite of that shown in FIG. 2, i.e. the upper valve part 118-, 122- of the return valve 72 will be closed while the upper part of the pressing valve 70 will be open. Hereby the air pressure will be transmitted through the bore 80 in the socket piece 14 and into the front pressing chamber 32, from where it will be further transmitted through the piston rod hole 28 and channel 26 to the rear pressing chamber 36. Thus, a pressing force will act on the rear side of both pistons 16 and 18 so as to press the piston system 16, 18, 20 forwardly with twice the power as in the return stroke. This movement is used for dr-iving out the putty from the front cylinder of the gun through. the nozzle 42. As soon as the trigger 98 is released the valve system will again assume its neutral position so that the operation of the gun may be interrupted when desired.

For charging the gun the piston system is pressed to its front position shown in dotted lines in FIG. 5, where the front piston 16 is situated almost at the outer end of the front cylinder 10. The end cover 38 is released from the cylinder mouth and swung back to its rear position as described hereinbefore and as shown in FIG. 5. The gun isheld in the position shown above a putty pail 150 and the mouth of the gun is lowered into contact with the surface of the putty. With a finger behind the trigger 98 the operator now pushes the trigger forwardly to thereby connect the return chamber 34 with the source of compressed air so' as to cause. the piston system to move upwardly in the gun. Hereby the gun will be sucked down into the putty, and the operator follows this movement of the gun. When the mouth of the front cylinder 10 has reached the bottom of the pail 150, or when the piston system has reached its hindmost position the operator pulls the gun up from the putty, preferably by giving it a slight turn for loosening any putty adhering to the exterior surface of the cylinder 10. For minimizing the risk of such adhering putty the surface of the cylinder 10 is preferably completely smooth, while also the securing or fastening means for the end cover 38 are located in good distance from the mouth of the cylinder so as to cause no troubles in this respect.- After having charged the gun in this manner the operator now brings the end cover 38 to its locked working position as described in connection with FIG. 4, whereafter the putty gun is ready for further use.

A modified embodiment is schematically shown in FIG. 6 and comprises a front cylinder 160 corresponding to the cylinder 10 in the embodiment described hereinbefore, an end cover 162 therefor, :a rear cylinder 164 of enlarged diameter behind a rigid wall ring portion 157, and two pistons 165, 166 located in the corresponding cylinder portions and rigidly interconnected by means of a piston rod 167. In a pistol grip there is provided a trigger operated valve system (not shown) corresponding. to the system already described and connected with both ends of the cylinder portion 164 by means of tubes 168 and 169 in such a manner that compressed air is introduced into the cylinder through the tube 169 when the trigger is pressed inwardly while the air is introduced through the tube 168 when the trigger is pushed forwardly.

It will be understood that when the trigger is pushed forwardly and compressed air is introduced into the space 158.between the two pistons 165 and 166 the pressure on the front side of the piston 166 will be higher than the pressure on the rear side of the piston 165-or rather the resulting-pressing force bigger-whereby the entire piston system will be forced backwardly to thereby perform the charging movement described in connection with the first mentioned embodiment. When on the other hand compressed air is introduced into the chamber 159 behind the piston 166 the piston system will be pressed forwardly to perform the working stroke of the system; also in this case the pressing force will be bigger than the retracting force due to the difference in the resulting piston area in the pressing chamber 159 and the return chamber 158.

The wall portion 157 may well be. inwardly extended so as to be closed around the piston rod 167; in this case, however, the room'behind the piston 165 must have an opening to the atmosphere.

A further embodiment is schematically illustrated in FIG. 7, where a gun cylinder 170 contains a non-rotatable but slidably arranged piston 172 adapted to be driven by a rotatable, screw threaded center spindle 173 mounted in a rib supported front bearing 174 and in a rear bearing in a wall 175. Behind this wall the spindle 173 has a gear wheel 176 in driving connection with a driving wheel 177 having a backwardly extending shaft 178 to be releaseably coupled to the chuck of a hand motor 179. When the motor 179 is activated the spindle 173 will be rotated so as to move the piston 172 in one direction. For enabling the piston to be driven in the reverse the motor 179 may 'be of the reversible type, or the gear wheels 176, 177 may form part of a gear wheel system provided with a handle for controlling the direction of rotation of the spindle 173 in case the shaft may be rotated in one direction only.

Also in the last described embodiments provisions may be made for enabling an adjustment of the velocity of the return stroke for adapting the performance to the requirements of the particular substance, for example more or less cold or viscid putty, such as obtained by means of the adjustment screw 78 in FIGS. 1-5. If desired a similar arrangement may be provided for adjusting the pressing force.

The invention is not limited to the embodiments and applications shown and described in the foregoing. For example, the device may be provided with a built-in electric motor whether of the rotating type or operating by axially travelling magnetic fields. The motor may also drive a pump for controlling the movements by means of a hydraulic system. In case of a sutficiently narrow end opening in the gun nozzle the gun will be applicable for fluids as well; in this case it may be charged without removing the end cover. Moreover, the dispenser cylinder may have separate dispenser and charging openings.

Instead of the two trigger operated valves the gun may be provided with a selector to be manually set for introducing the drive medium into either the pressing chamber or the return chamber in response to the opening of a common operation valve.

The return stroke of the piston system may be controlled from another power source than used for the pressing movement, even by means of a force such as a spring force accumulated during the pressing movement.

I claim:

1. A power driven putty gun for plastic substances of relatively high viscosity comprising a dispenser cylinder having a dispenser opening at one end, a piston reciprocally arranged inside said cylinder, power operated means for selectively moving said piston towards or away from said cylinder end opening, holding means located adjacent said dispenser cylinder at a distance from said cylinder end, cover means movable between an operative position in engagement with and covering said open cylinder end and an inoperative position at a distance from said cylinder end, and connecting means operable to releasably interconnect said cover means and said holding means in said operative position of said cover means, the exterior surface of said cylinder being substantially completely smooth adjacent said open end thereof.

2. A power driven putty gun for plastic substances comprising a dispenser cylinder being open in one end, a piston reciprocally arranged inside said cylinder, power operated means selectively operable to move said piston in opposite axial directions between a front position adjacent said cylinder end and a rear position in said cylinder, exterior pivot means located behind said rear position of said piston, means operable to move said pivot means over a relatively short axial distance between an advanced position and a retracted position, cover means operable to cover the said open end of said cylinder, said cover means having a cover portion provided with a dispenser opening of reduced diameter relatively to said cylinder and a cylindrical flange portion, said flange portion being engageable with and releasable from the open cylinder mouth in response to mutual axial movements therebetween, said cover means and said pivot means being interconnected by lever means swingably secured in one end to said pivot means, said cover means being rigidly secured to the other end of said lever means at such a distance from the pivot means that the said flange portion of said cover means is situated entirely without said cylinder mouth when said pivot means assume said advanced position while in the retracted position of said pivot means the flange portion is sufficiently retracted to operatively engage said cylinder mouth, whereas the exterior surface of said cylinder is substantially completely smooth between the said end thereof and the plane of the said piston in the rear position thereof.

3. A power driven putty gun comprising a dispenser cylinder having a front end and a rear end, a dispenser opening and a charging opening being located in said front end, a first piston reciprocally arranged inside said dispenser cylinder, said rear end of said dispenser cylinder opening through a blocking means into a rear I cylinder of enlarged diameter relatively to said dispenser cylinder, at second piston reciprocally arranged inside said rear cylinder of enlarged diameter, a piston rod rigidly interconnecting said first piston and said second piston, a

return chamber constituted by the room between the said second piston and said blocking means, a rigid rear wall in said rear cylinder of enlarged diameter, apressure chamber constituted by the room between said second piston and said rear wall, and means operable to selectively connect either of said return chamber or said pressure chamber to an external pressure medium source.

4. A power driven putty gun comprising a dispenser cylinder having an opening adjacent the front end thereof,

J a piston reciprocally arranged inside said cylinder, power intake means operatively connectible with external power supply means, first power operated means operable to urge said piston in one axial direction, second power operated means operable to urge said piston in' the opposite axial direction, switch means operable to selectively connect either said first or said second power operated means to said power intake means, and means included in the power connection between said switch means and said second power operated means effectively providing for a reduction in the power supply for said second power operated means relatively to the power supply available for said first power operated means.

5. A power driven putty gun comprising a dispenser cylinder having an opening adjacent the front end thereof, a piston reciprocally arranged inside said cylinder, power intake means operatively connectible with external power supply means, first power operated means operable to urge said piston in one axial direction, second power operated means operable to urge said piston in the opposite axial direction, switch means operable to selectively connect either said first or said second power operated means to said power intake means, and adjustable regulation means included in the power connection between said switch means and at least one of said first or second power operated means operable to adjust the power supply available for said power operated means.

6. A power driven putty gun for high viscosity plastic substances comprising a cylindrical dispenser container having a discharge opening in one end thereof and being engaged to a socket piece at the other end, a cylindrical return chamber having a closed end wall and having the other end thereof secured to said socket piece with the axis of said dispenser container and said return cylinder aligned, a first piston reciprocally mounted within said cylindrical dispenser container, a second piston reciprocally mounted within said return cylinder, a piston rod extending between said first and second pistons, and coupling said pistons together for conjoint movement, said piston rod having an axial bore extending through said second piston and said rod, and including an orifice coupling said bore to said dispenser container adjacent said first piston, and means to introduce air under pressure into said return cylinder to urge said pistons in a return stroke away from said discharge orifice, and means to introduce air into ,said dispenser container to exert pressure on said first piston and through said orifice and bore in said piston rod on said second piston thereby to urge said pistons towards said discharge orifice in a power stroke having twice the force of the return stroke.

References Cited by the Examiner UNITED STATES PATENTS 1,210,179 12/1916 Lewis 222389 X 2,692,706 10/ 1954 Wiksten 222389 X M. HENSON WOOD, JR., Primary Examiner.

LOUIS I. DEMBO, Examiner.

A. N. KNOWLES, Alssistant Examiner. 

4. A POWER DRIVEN PUTTY GUN COMPRISING A DISPENSER CYLINDER HAVING AN OPENING ADJACENT THE FRONT END THEREOF, A PISTON RECIPROCALLY ARRANGED INSIDE SAID CYLINDER, POWER INTAKE MEANS OPERATIVELY CONNECTIBLE WITH EXTERNAL POWER SUPPLY MEANS, FIRST POWER OPERATED MEANS OPERABLE TO URGE SAID PISTON IN ONE AXIAL DIRECTION, SECOND POWER OPERATED MEANS OPERABLE TO URGE SAID PISTON IN THE OPPOSITE AXIAL DIRECTION, SWITCH MEANS OPERABLE TO SELECTIVELY CONNECT EITHER SAID FIRST OR SAID SECOND POWER OPERATED MEANS TO SAID POWER INTAKE MEANS, AND MEANS INCLUDED IN THE POWER CONNECTION BETWEEN SAID SWITCH MEANS AND SAID SECOND POWER OPERATED MEANS EFFECTIVELY PROVIDING FOR A REDUCTION IN THE POWER SUPPLY FOR SAID SECOND POWER OPERATED MEANS RELATIVELY TO THE POWER SUPPLY AVAILABLE FOR SAID FIRST POWER OPERATED MEANS. 